Bolt-anchor.



PATENTED JAN. 15, 1907.

F. C. PALMER. BOLT ANCHOR. APPLICATION FILED 00T.10. 1905.

MM: c. 021M410,

Attest. Inventor. QeO/k/ A! y M1- 7 UNITED STATES PATENT orrron.

Specification of Letters Patent.

Patented Jan. 15, 1907.

- Application filed October 10, 1905. Serial No. 282,101.

tion of a bolt placed in a wall, but not exanded, a plate held to the wall by the bolt (313g shown in vertical section. Fig. 2 is a si ar view showing the anchor slightl expanded. Fig. 3 is a partial section an top plan view of the'parts shown in Fig. 1 below hie d the plane of contact of the two s s. Fig. 4 is a side elevation of the separable bushing, and Fig. 5 is a central section thereof, Fig. 6 is a section on the plane of the line 6 6 in Fig. 1. Fig. 7 is a side elevation, and Fig. 8 is a plan view, of the interior thereof. Fig. 9 is a central section of a modified form of the separable bushing.

In the drawings, 10 10 are shields made of an suitable kind of soft metal and cast, rol ed, or stamped into shape. Each shield constitutes a longitudinal segment of a cylinder, polyhedron, or other similar symmet rical solid. Each shield tapers slightly outward internally at its inner end 11 11, and each is provided with recesses, notches, or slots 12 12 for the reception of the Wedges 22 of thebushing 20, hereinafter referred to. Each shield is preferably provided with means, as the projections 13 13 and corre sponding recesses 14 14, whereby accurate registration of the parts may be secured upon assembling them. These shields may be of any convenient number. In the form of anchor illustrated only two are shown. It is essential, however, that when assembled they should form a hollow symmetrical sleeve, which should referably taper outwardly slightly at its inner end.

assembled shields is smooth and free from all projections. The outer surfaces of the shie ds may be smooth or rough, as may be preferred.

20 is a separable tubular bushing slightly conical or taperin being lar er externally at its inner end. It is internal y threaded at It will be observed that the internal surface of the 21 with female threads. Externally it is provided with a plurality of wedges 22, made inte ral with the body of the bushing or firm y secured thereto.

In Fig. 9 there is illustrated my improved form of the bushing 20, which is provided internally with a plurality of female threads, one series, 210, being cut to one gage and another series, 211, being cut to another gage which may be a simple multiple of the first gage. For instance, the threads 210 210 are shown cut approximately eight to the inch, while the threads 211 211 are shown cut approximately sixteen to the inch.

30 is a screw or bolt desired to be inserted into the aperture in the wall 31.

32 is a plate or other thing which it is desired to hold against the wall, and 33 is the head of the screw or bolt 30.

The manner of using the device is as follows: The parts are. first assembled, as shown in Figs. 1 and 3, the tubular bushing 20 being placed within the inner endof the sleeve formed by the assembled shields. The parts fit loosely and are easily placed into position. The screw or bolt 30 may be it may be inserted .afterward. The parts being assembled, the screw or bolt is rotated until the inner edges of its head 33 abut snugly against the plate 32. Its further rotation in that direction being thus prevented, and because of the fact that its threads engage with the threads with which the bushing 20 is internally provided, tends to draw forward this bushing. As this forward movement continues the parts assume the position shown in Fig. 2, thewedges 22 of the bushing acting against the sides of the shields 10 10 to force them apart and against the walls of the aperture in which they are placed. A further rotation of the parts tightens them securely into position.

It will be noted that as the tubular bushing is relatively small compared with the shields (and might be made even smaller than shown in the illustration) by providing a number of these bushings with a set of shields capable of being assembled into one sleeve a wide range of usefulness may be secured for the device. can about double its efiiciency and range of usefulness by cutting in the same bushing a plurality of threads, as illustrated in Fig. 9, 1 10 so that more than one standard of thread may be employed with the same bushing.

inserted in the parts as they are assembled, or

I find, however, that I -rality of threads cut to different ga es, each thread extending from end to en of the bushing.

2. Abolt-anehor, eomprisin aplurality of shields adapted, when assembded, to form a sleeve and a tubular bushing inclosed by the sleeve and provided with a plurality of internal threads out to different gages, the different threads being out in the same length of the bushing.

3. A bolt-anchor, comprising a lurality of shields, adapted, when assemble to' form a sleeve and an internally-threaded tubular 2o bushing inolosed by the sleeve, the threads within the bushing being cut to different gages, the gage of one thread being a simple multiple 0 the gage of another thread.

In testimony whereof I'aflix my signature 2 5 in presence of two witnesses.

FREDERICK O. PALMER. Witnesses:

WILLIAM R. BAIRD, ALAN MCDONNELL. 

